Electromagnetic brake.



No. 775,886. PATENTED NOV. 22, 1904. R. U. LOWRY.

ELECTROMAGNETIC BRAKE.

APPLICATION FILED AUG, 13. 1903.

N0 MODEL. 2 sums-441mm 1.

No. 775,885. PATENTED NOV. 22, 1904.

R. O. LOWRY.

ELECTROMAGNETIC BRAKE.

APPLICATION FILED AUG. 1a, 1903.

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Patented November 22, 1904.

PATENT OFFICE.

ROBERT C. LOWRY, OF NEW WESTMINSTER, CANADA.

ELECTROMAGNETIC BRAKE,

SPECIFICATION forming part of Letters Patent No. 775,835, dated November22, 1904.

Application filed August 13, 1908. Serial No- 169,388. (No model.)

To (Ll/1 whom, it may concern:

Be it known that l, ROBERT C. Lower, a subject of the King of GreatBritain, residing at New Westminster, in British Columbia, have inventedcertain new and useful Improvements in Electromagnetic Brakes, of whichthe following is a specification.

My invention relates to electric magnetic brakes for railwayrolling-stock.

Amongthe objects of the invention is to provide a compact, cheap, andpowerful electric brake of variable force applicable to the magnetizedwheels of vehicles moving on or over rails.

Other objects and advantages of the invention will be apparent from thefollowing description when taken in connection with the accompanyingdrawings.

The invention consists in the novel construction, arrangement, andcombination of parts, as hereinafter fully described, illustrated in thedrawings, and pointed out in the appended claims.

In the accompanying drawings, Figure 1 is a side elevation of acar-truck, showing my improved brake device in the position it as sumeswhen the brake is applied. Fig. 2 is a similar View, the parts being inthe position they assume when the brake is oiT. Fig. 3 is a plan view ofthe parts seen in Fig. 1. Fig. 4 is a side view of aslightly-modifiedform of coherer-bar. Fig. 5 is a similar view of a further modified formof coherer-bar.

In the drawings, 1 indicates the Wheels of car-truck on the same rail,said wheels being magnetized and of opposite polarity or sign. No claimis herein made to any specific means for magnetizing the car-wheel. Thismay be accomplished in any suitable manner-such, for instance, as bymeans of coils thereon. Arranged intermediate the car-wheels on one sideor both sides of the truck is a suspending device adapted to support thebrake mechanism. This suspending device comprises in the presentinstance checks or hangers 2, preferably of non-magnetic metal, whichmay be supported by any suitable means from the car-body or from somepart of the truck. For instance, 1 show the cheeks as depending from aplate 3, bolted to beam 4: of the truck.

over the road. For attaining this object I provide a bolt'6of steel, forinstance-extending transversely of the checks of the suspending device.The ends of the bolt are seated in slide-boxes 7, which are adapted forup-and-down movement within vertical slots 8, provided in the cheeks ofthe suspending device. Coiled springs 9 are arranged within the slotsand bearing upon opposite sides of the slide-boxes, whereby to provide ayielding connection of the slide-boxes with the checks or hangers.

The coherer-bar 5 is arranged in the oblique position shown, with itsopposite ends lying respectively above and below the centers of thecar-wheel axles. The bar is provided toward each end with a projection11, the face of which toward the periphery of the adj accnt car-wheel iscurved. 1 preferably provide a projection of semicircular shape 12,though the shape of this projection may be varied. For instance, in Fig.1 I show the bar as terminating in a bearing edge or surface 13, saidsurface being concave to it and be in contact with a portion ofperiphery of wheel. The general shape of the bar seen in Fig. 4 may beslightly modified, as shown in Fig. 5, where I show it as beingthickened at the points 14. whereby to strengthen the bar at the pointswhere it is subjected to the most strain when the brake-shoes areapplied. Any other form of bar might be used instead of the forms shown,and I do not wish to be limited to any particular form.

15 indicates brake-shoes pivotally carried one at each end of thecoherer-bar. The shape of the brake-shoes may be somewhat varied, thoughin the present instance I show each shoe as having a long curved hearingor brake surface 16, which is adapted to come into contact with theperiphery of the car-wheel, the shoe being formed with cheeks, which fitagainst sides of coherer-bar. Each brake-shoe is pivotally carried onthe coherer-bar by a bolt 17, on which bolt the brake-shoe is adapted torock. Each brake-shoe is of some nonmagnetic material. Thus thebrake-shoes do not become magnetized when the magnetic current is passedthrough the device. and in this respect my present invention differsfrom other brake devices of this character.

A lug or projection 18 is provided on each end of the coherer-bar. Fixedin this lug is a guide bolt or pin 18 of circular section, which passesinto a hole of slightly-larger diameter in the brake-shoe. Carried bythe bolt and encircling it are coil-springs 19, which press against thelug 18 and the brake-shoe. When the brake is applied,these springsbecome compressed and the brake-shoe acts with greater or lessfrictional effect on the truck-wheels, the effect being in proportion tothe strength of the magnetism in the latter; but as soon as thecoherer-bar assumes the position shown in Fig. 2 the springs will relaxand rock the shoes on their pivotal bolts 17. To permit and limit theswinging movement of the brake-shoes on the coherer-bar, I provide slots20 in the checks of each shoe, so that the bolts 21, affixed tocoherer-bar, which extend through the checks of the shoes and have abearing in the said slots, may ride freely in said slots.

Mounted upon and surrounding the cohererbar are demagnetizing-coils 22.These are coils of insulated copper wire wound continuously, and theirends are in practice to be connected through a suitable controller witha source of electricity. Neither controller nor electric source isshown, as it is not necessary for the purpose of illustrating myinvention, it being suflicient to state that a current of electricityhas to be turned into these coils to demagnetize the coherer-bar when itis desired to throw the brake out of action. The current and circuit maybe derived or taken from any suitable source. To apply the brakes, allelectric current is out out of the demagnetizing-coils on thecoherer-bar, and the wheels of the trucks being magnetized the ends ofthe coherer-bar approach said wheels and bring the brake-shoes intocontact with the peripheries of said wheels, and friction betweenbrake-shoes and said peripheries ensues. When the truck-wheels are morestrongly magnetized, the attraction between the latter and thecoherer-bar increases, and the approach of the two together is resistedby the springs reacting on the brake-shoes, causing increased frictionbetween shoes and wheels. If stronger braking effect is desired, themagnetization of truck wheels is increased, and the ends of the bar willthen pass through the brake-shoes completely and come into directcontact with the peripheries of the wheels, stopping the revolution ofthe latter.

It will be understood that one object for my employing thedemagnetizing-coils 22 is to eliminate the effect on the coherer-bar ofresidual magnetism in the truck-wheels. In magnetic wheels of cast-iron,for example, such magnetism will generally be present. The coils 22 willbe so wound that each pole or end of the coherer-bar will be of likemagnetic polarity or sign to that in the wheel with which such end comesin contact. After cutting out the current magnetizing the wheels acurrent of electricity will be sent through the demagnetizing-coils, andthe ends of the coherer-bar will no longer be attracted to thetruck-wheels. A spring 24, which I provide, will then pull the end ofthe coherer-bar out of the magnetic range, and so hold it back. Thisspring 24 is secured at one end to the coherer-bar and at its oppositeend to a bolt 25, which is seated in the cheeks or hangers 2. Thecoherer-bar, it will be understood, is by means of such spring held backout of contact with the wheels. Another object for my employing thedemagnetizing-coils 22 is to prevent the approach of the coherer-bar tothe wheels when magnetism of the latter is desired and brake action isnot wanted. In this case it will be necessary to have a flow of currentthrough the demagnetizing-coils as long as the wheels are to remainmagnetized and the brakes to be kept off them.

It will be seen from the construction described that the action producedby gradually increasing magnetism in the wheels (which magnetic efiect,it is assumed, is under control) has the effect ultimately not only ofsecuring the resistance due to a frictional shoe pressing upon theperiphery of each wheel, but also gives a very powerful resistance onperiphery when the end of coherer-bar comes into contact with said wheeland conducts lines of magnetic force, affording a brake of the strongestpossible character, which will bring the car to a standstill within ashort space. The particular manner of arranging the coherer-bar andbrake-shoes in connection with magnetized wheels enables me to obtain avery effective braking action. The wheels brake on each other and at thesame time on the rails, and there is no appreciable strain in the bodyof the car or in the axles due to the action of the brake, as is thecase with the usual construction of brakes of this character. It will benoted, too, that in my construction I dispense with brake-beams, rods,or other attachments such as are usually found in brake devices.

WVhat I claim as new, and desire to secure by Letters Patent, is I 1. Inan electromagnetic brake a bar arranged between and adapted to come indirect contact with the peripheries of the wheels as described,brake-shoes carried by said bar, a

suspending device, and means to permit the bar to have a movementrelatively to the suspending device, for the purpose set forth.

2. In an electromagnetic brake, a bar arranged between the wheels asdescribed, brakeshoes carried by said bar, a suspending device and meansacting on the bar to cause its ends to move away from the peripheries ofthe wheels when the polarity of said bar is changed.

3. In an electromagnetic brake, a bar arranged between the wheels asdescribed, nonmagnetic brake-shoes carried by said bar, the ends of saidbar being adapted to come in direct contact with the peripheries of thewheels.

4. In an electromagnetic brake, a bar arranged between the wheels asdescribed, depending eheeks orhangers provided each with a verticalslot, slide-boxes adapted to travel in said slots, a bolt having itsends seated in said boxes and upon which bolt the said bar is mountedand springs arranged to bear upon opposite sides of the slide-boxes.

5. In an electromagnetic brake, a bar arranged between the wheels asdescribed, brakeshoes pivotally mounted on the bar and each providedwith a slot through which an end of the bar is adapted to project so asto come into contact with the periphery of a wheel.

6. In an electromagnetic brake, a bar arranged between the wheels asdescribed and coils mounted upon the bar and adapted to demagnetize thebar when the car-wheels are magnetized or for magnetizing said bar whensaid wheels are magnetized.

In testimony whereof I aflix my signature in presence of two witnesses.

ROBERT C. LOWRY.

Witnesses:

WALTER B. lVI-IITCOMB, RoLLo Wnrrcom.

